Auto Bravado's ideas on the the Trucks or Cars Miles per Gallon: We all want better numbers, but do we really know how to get them? Let us learn that to get results is to have fun! There are tricks that it took many mechanics decades of experience to figure out and perfect.

Saturday, June 3, 2017

When
the space for the ceramic looks much deeper, there is actually more
total insulation against the heat going out of the back of the spark
plug and into the engine compartment. This determines the heat of the
plug, not whether it's made out of iridium, platinum, copper, or even
nickel like on my old 89 Yamaha XT600 Spark Plug. (Related video)

In
the case of my 2004 Nissan Frontier, I noticed that one of the old
spark plugs was a colder temperature index of 5 instead of 9. On
NGK's it's very easy to tell the temperature ranges as a 1 is
coldest, a 9 is the hottest, like what is supposed to be in my Nissan
Frontier, but this was a 5, which was probably making for a little
spark knock as the spark plug wasn't staying hot enough, unlike it's
5 other friends who were doing more of the work. The slight miss of
this engine for the last several years? Mystery solved!

Side
note: I hate anti-seize. As it ages, it becomes anti-remove, or
whatever you want to say about how it makes it hard to remove a spark
plug!

What
are some reasons you'd change your heat ranges? A lot of people
assume hotter means more performance, but as you can see for my
Nissan Frontier, they've already chosen the hottest plug. The truth
is, you're not going to be able to do better than what the
manufacturer decided you needed for the heat range of your engine
unless you've done significant modifications, which may change the
needs of your engine.

Most
commonly, people go colder on the heat range of their spark plug
because of forced induction, be it a super charger or turbo charger,
with great over all engine temperatures, having a lower heat range on
the spark plug can be a preventative against knock or more minor
power losing per-ignition.

I've
seen people do okay with a hotter plug a lot of times when they
always short tripped their vehicle or for some reason the engine was
staying too cold, but honestly, they're usually lying to themselves.
I bought a more expensive plug, it's hotter? No, if you check how the
manufacturer rates the heat ranges, you'll find it's pretty difficult
to buy plugs that are even in the wrong heat range unless you do a
special order, knowing how the numbers for that spark plug
manufacturer and how they tell you what heat range it is.

Let's
get back to why I say people are lying to themselves. You see, just
because it's an iridium and it gets a better spark, it doesn't mean
you've actually changed the heat range of your spark plug! That's
spark. The heat range is the temperature of the spark plug when it's
NOT igniting the fuel/air mixture.

If a visual and practical example, help you learn, be sure to check out my video about this below: